Method for improving 3 dimensional effect and reducing visual fatigue and apparatus enabling the same

Abstract

A method and an apparatus for improving three dimensional (3D) effect of a 3D image collected by a 3D photographing apparatus, and reducing visual fatigue, are provided. A feature point of a left-eye image entering through a left-eye lens and of a right-eye image entering through a right-eye lens is acquired, a disparity between the left- and right-eye images is detected, a distance between the left- and right-eye lenses is controlled so that the disparity between the left- and right-eye images becomes a previously-set reference disparity, and at least one of the left- and right-eye images is shifted so that a convergence point is placed on an object located within the left- and right-eye images.

What is claimed is: 
     
       1. A method for controlling a three dimensional (3D) photographing apparatus, the method comprising:
 acquiring a feature point of a left-eye image entering through a left-eye lens, and a feature point of a right-eye image entering through a right-eye lens; 
 detecting a disparity between the left- and right-eye images by comparing the feature points of the left- and right-eye images; 
 controlling a distance between the left- and right-eye lenses so that the disparity between the left- and right-eye images becomes a previously-set reference disparity; and 
 shifting at least one of the left- and right-eye images so that a convergence point is placed on a first object located within the left- and right-eye images, 
 wherein the detecting comprises: 
 determining a number of frames of a previous left-eye image or a previous right-eye image based on an intensity of illumination of the left- or right-eye image; and 
 determining a consistency of disparity between the left- and right-eye images using the frames of the previous left- or right-eye images. 
 
     
     
       2. The method of  claim 1 , wherein the specific object exists in an auto-focus area, and the shifting includes shifting at least one of the left- and right-eye images so that a disparity is at a minimum between the feature points existing in the left- and right-eye images with respect to the first object. 
     
     
       3. The method of  claim 1 , wherein the controlling includes moving at least one of the left- and right-eye lenses in a substantially perpendicular direction with respect to an optical axis. 
     
     
       4. The method of  claim 3 , wherein the moving includes moving at least one of the left- and right-eye lenses within a previously-set maximum time. 
     
     
       5. The method of  claim 1 , wherein if the disparity of the first object is at the minimum, at least a second object has a negative disparity, and at least a third object has a positive disparity. 
     
     
       6. The method of  claim 5 , wherein, with reference to the left- and right-eye lenses, the at least a second object is located in front of the first object, and the at least a third object is located in back of the first object, or the at least a second object is located in back of the first object, and the at least a third object is located in front of the first object. 
     
     
       7. The method of  claim 1 , wherein the controlling includes comparing the disparity between the left- and right-eye images with a previously-set reference disparity so that the disparity between the left- and right-eye images becomes the previously-set reference disparity, and
 the previously-set reference disparity (dref) is defined by:
   max{( d max− d conv),( d conv− d min)}≈ d ref
 
 
 where, dmax is a maximum disparity, dmin is a minimum disparity, and dconv is a disparity of the first object. 
 
     
     
       8. The method of  claim 1 , wherein the detecting includes detecting the disparity between the left- and right-eye images using an accumulated histogram with respect to a plurality of disparities between the left- and right-eye images. 
     
     
       9. The method of  claim 7 , wherein the previously-set reference disparity (dref) is a value between 30 and 40 minutes,
 the previously-set reference disparity is a difference of convergence angles between when a lens is focused on a plane of a screen and when the lens is defocused on the plane of the screen, and 
 the convergence angle represents an angle between the lenses when the left- and right-eye lenses are focused on the first object. 
 
     
     
       10. The method of  claim 1 , wherein the determining includes reducing the number of frames of the previous left- or right-eye image when the intensity of illumination is high, and increases the number of frames of the previous left- or right-eye image when the intensity of illumination is low. 
     
     
       11. A three dimensional (3D) photographing apparatus, comprising:
 an acquiring unit which acquires a feature point of a left-eye image entering through a left-eye lens, and a feature point of a right-eye image entering through a right-eye lens; 
 a detecting unit which detects a disparity between the left- and right-eye images by comparing the feature points of the left- and right-eye images; 
 a control unit which controls a distance between the left- and right-eye lenses so that the disparity between the left- and right-eye images becomes a previously-set reference disparity, and shifts at least one of the left- and right-eye images so that a convergence point is placed on a first object located within the left- and right-eye images, 
 wherein the control unit compares the disparity between the left- and right-eye images with a previously-set reference disparity so that the disparity between the left- and right-eye images becomes the previously-set reference disparity, and 
 the previously-set reference disparity (dref) is defined by:
   max{( d max− d conv),( d conv− d min)}≈ d ref
 
 
 where, dmax is a maximum disparity, dmin is a minimum disparity, and dconv is a disparity of the object. 
 
     
     
       12. The 3D photographing apparatus of  claim 11 , wherein the specific object exists in an auto-focus area, and the control unit shifts at least one of the left- and right-eye images so that a disparity is at a minimum between the feature points existing in the left- and right-eye images with respect to the object. 
     
     
       13. The 3D photographing apparatus of  claim 11 , wherein the control unit moves at least one of the left- and right-eye lenses in a substantially perpendicular direction with respect to an optical axis. 
     
     
       14. The 3D photographing apparatus of  claim 13 , wherein the control unit moves at least one of the left- and right-eye lenses within a previously-set maximum time. 
     
     
       15. The 3D photographing apparatus of  claim 11 , wherein the previously-set reference disparity (dref) is a value between 30 and 40 minutes,
 the previously-set reference disparity is a difference of convergence angles between when a lens is focused on a plane of a screen and when the lens is defocused on the plane of the screen, and 
 the convergence angle represents an angle between the lenses when the left- and right-eye lenses are focused on the object. 
 
     
     
       16. The 3D photographing apparatus of  claim 11 , wherein an indicator is provided to indicate degree of visual fatigue according to the disparity, and the 3D photographing apparatus further comprises a display unit which displays a recommendation according to the indicator. 
     
     
       17. A non-transitory computer-readable recording medium having recorded thereon a computer program for executing a method of controlling a three dimensional (3D) photographing apparatus, the method comprising:
 acquiring a feature point of a left-eye image entering through a left-eye lens, and a feature point of a right-eye image entering through a right-eye lens; 
 detecting a disparity between the left- and right-eye images by comparing the feature points of the left- and right-eye images; 
 controlling a distance between the left- and right-eye lenses so that the disparity between the left- and right-eye images becomes a previously-set reference disparity; and 
 shifting at least one of the left- and right-eye images so that a convergence point is placed on a first object located within the left- and right-eye images 
 wherein the detecting comprises: 
 determining a number of frames of a previous left-eye image or a previous right-eye image based on an intensity of illumination of the left- or right-eye image; and 
 determining a consistency of disparity between the left- and right-eye images using the frames of the previous left- or right-eye images.